This invention relates generally to a lightweight, dimensionally stable, impact resistant, strong and rigid door assembly which is resistant to warpage.
For many years residential exterior doors have been fabricated from wood with attendant disadvantages from the standpoint of insulating characteristics and tendencies to warp or delaminate. Recently, door assemblies having outer panels or skins comprised of plastic and other materials have been coming into increased use. U.S. Pat. No. 4,550,540 discloses a door assembly having a frame, a foamed core, and polyester compression molded skins. U.S. Pat. No. 4,152,876 discloses a metal faced door comprising a frame, a foamed core, and metal faces. However, these doors suffer from several disadvantages. Metal faced doors are relatively heavy and the metal faces need to be preformed to rather exacting dimensional standards to properly fit the frame. The doors having skins of polyester, due to the relatively poor resistance to impact of polyester resins, generally are somewhat susceptible to damage, e.g., breakage or cracking of the skins, when subjected to impact.
The door assemblies of the instant invention overcome the deficiencies and problems associated with presently available doors. They are resistant to warpage; they have insulating properties; they are able to withstand relatively high impact forces without breaking or cracking; they are relatively light weight; and they are easy to assemble.